It is known that the demands of customers regarding the shifting comfort of automatic transmissions is constantly increasing. However, transmission manufacturers and their suppliers can only manufacture transmission parts to certain tolerances because of cost and production reasons. Therefore, it is typical to implement corrections to shifting, or to individual phases of shifting, via an electronic transmission control in order to ensure a high level of shifting quality for the entire life of the transmission, regardless of wear, degradation, and changing environmental conditions. These corrections (adaptations) take undesired alterations to the shifting progression into account that occur, for example, because of component tolerances, changes in lamella friction values, and mechanical wear within the automatic transmission. Parameters controlling these adaptations are usually stored in a transmission-control adaptation buffer, and form so-called adaptation characteristic mapping.
These mappings generally include two different axes, according to which the characteristic mapping parameters are divided into two classes. It is usual for the system to alter these mappings to “learn” from external events. This means that the mapping is empty (or at a base state) when operation begins. For each occurring event that may be assigned to a class, it is determined via external sensors whether the event occurred in the desired manner, or whether it occurred in a manner worse than expected. Depending on the event, each class of characteristic mapping is moved one adaptation step upward, one adaptation step downward, or not moved at all.
To date, the art has sought to achieve the most accurate results possible, typically using a large number of adaptations. However, the fact that a connection may exist between various adaptations has not been taken into account, but rather several adaptations were performed simultaneously without taking potential connections into account.